Auto-LPG Conversion Thread

[ghosthunter]

...adjusted to advanced timing for ignition, (since i think lpg has higher octane.. anyone for this correction...),

well, to maximize engine performance, an adjustment to the ignition timing to take advantage of the higher octane value. But this would result in the engine running very rough if you switch back to gasoline.

How many degrees did you advance the ignition from stock?

your post prior to this one is an interesting one. gave me a lot of thinking about upgrading to a better oil. may just be the answer i need. thanks!

Even the current corolla engines have sludge problems and those were running on gasoline.

i thought i mention that lpg has better fuel cost than on gasoline... i alone do the adjustments for the lpg on all our 44 taxis(n still aquiring more). sparkplug color is orange with most. some with red(some drivers prefer their rides faster). white colored sparkplug meant lean n higher temps. black.. rich af mix. im aware of these conditions atleast.

Your sparkplugs are telling you that those engines are running lean. That also might be the cause of your increase valve seal wear. In the very least, it would result in slightly higher engine coolant temperatures.

BTW, the locally available LPG kits used on most cars are very sensitive to air filter condition/quality. A slightly clogged filter will result in a richer air/fuel ratio and also less power from the engine. I tend to clean/replace my filter a bit more often than before. Maybe this could be the root of your problem?

[ghosthunter]

yes i do. its really not much. i and my dad maintain 44 units of taxi,(along with 1-3 helper/s), all running in lpg. it's not really that often that i change headgaskets on a xl corolla with a 2e engine. but compared with the gasoline, sludge build up is more evident on lpg. i've also worked on 4g13s on a lancer el(we have 4units among the 44). same find. then about 4units of sentra series III among the units with the surplus blacktop engine. ive only had about 2 times replacement of the head gasket with the same sludge buildup. ive never really opened the engine for the sentra back when it ran on gasoline. i'll try to get pics next time i have a headgasket replaced.

good for you that you know how to tune your own car. not everyone knows how to thinker with their engines.

with the macro lpg, the lpg flow is controlled by the "rpm" tick given off by the distributer. when u turn the key to on, it will let lpg flow for a few seconds then cut off. i had a chance to work with only 2 naiadss kit and i find that it consistently gives lpg flow to the carb once the key is set to on. i was on the impression that it gave a consistent flow to the carb regardless of rpm the engine was on. thanks for this correction.

The naiadss system seems to be a simpler system. The problem is controlling the flow of fuel to the engine's intake. The system can be controlled via two screws. One is located on the LPG evaporator. This controls the lpg idle flow rate. The second is located on the venturi adapter. This one controls the actual flow to the engine. This second screw is easy to screw up resulting in a possible lean burning engine at medium to higher RPMs.

Does the MACRO system have a similar setup to control the flow?

[dencio1976]

The naiadss system seems to be a simpler system. The problem is controlling the flow of fuel to the engine's intake. The system can be controlled via two screws. One is located on the LPG evaporator. This controls the lpg idle flow rate. The second is located on the venturi adapter. This one controls the actual flow to the engine. This second screw is easy to screw up resulting in a possible lean burning engine at medium to higher RPMs.

Does the MACRO system have a similar setup to control the flow?

yup. almost the same system. 2screws with addition, an rpm feedback from the distributor to the solenoids controlling the opening of the tank to the regulator, regulator to last screw before it entered the carb. low rpm, low frequency current therefore impeding the opening of the solenoids. then higher rpm, higher freq, max opening of the solenoids. the regulator that naiadss has does seem to have more adjustables thou. allen wrench screw type i think. if i was to further thinker with the macro regulator, i was thinking of getting the equivalent of cold air intake. but even with this addition, i've heard of naiadss kit taxis can also rival macro's consumption. so when it came to potential, same potential can be said for both kits for their 1st gen kits for carbs. works almost like a simple carb on a lawn mower.

i conducted a survey with the drivers about lpg consumption during hot days, regular days and rainy/cold days. relatively, it came out that drivers get the most kms/liter during colder days rather than on hot days. so with that in mind, i came with the idea of replicating it thru other means. do you feel this same effect on colder days? drivers have different feedbacks but it was noted with most of them to agree with that said.

last year, macro guys forgot to put water in the radiator one of the our first taxis installed with lpg kit. that made the the regulator cool. this moment came back to me when i thought about giving the engine cold air intake. then, with macro's latest design with the fuel injected type lpg kit (as i saw it being installed on a chevy van 6cyl and a ford expedition 8cyl), they were measuring water temp of the radiator. which got me to think that they might be on to this thought as well. im still feeling too lazy to continue with this project so i was thinking.. with the complex looking (more than the macro regulator anyways) regulator of naiadss, might it have ways of impeding water flow as well? for macro there none for sure with their 1st gen kit for carbs. or atleast i think it's their 1st gen kit.

this is regarding lpg consumption. record i have with one taxi is 250kms with 500pesos worth of lpg at P21+ that's about 10.5km/liter of lpg. ive had more than 3 cases like these consumption but this is the most km per liter i got as feedback with 1 driver. on average i get feedback of 3pesos/km on average. that's about ~7.5 kms/liter. what about for you?

im trying to get a more consistent consumption by any means necessary. i hear that the fuel injection type gets more for the kms/liter. not too sure thou. just rumors from drivers who knows drivers who have driven cabs with this system.

[dencio1976]

it's true with the toyota engines regarding sludge problems. ive used low oil grades before and even now. im thinking i got away with it since i had drivers using premium gasoline before. the post regarding lubrication in premium gasoline may have been the key why i didnt get sludge problems with premium as compared with unleaded n lpg. ill be experimenting with the best suited oil. be trying toyota motor oils. i hear even some eg hatchback racers use this oil. any confirmation on this?

i cant have semi synthetics or full synthetic oils as options for now. i change oil every 2weeks to a month depending on the color of oil.

air filter change can be as fast as less than a month for our taxis. less air to pull in thru the intake meant more lpg to be pulled thru. therefore af is rich. but then engine would run cooler? wont it?

if it's color orange with the sparkplug that's the average color of what you'll find on taxi's because it seems to be the one with the best km/liter consumption. with a private car, this would be ok to lean. preferred with red colored sparkplugs to run cooler. this may definitely be one reason why engine temps run higher. but then again if u turn it to red, consumption aint as efficient as compared with the orange colored sparkplug.

what color of sparkplugs do you have normally on your lpg cars?

im seeing 2 potential problems now, low grade oil and lean mix(orange). with the 1st potential prob, that's easy. few additional pesos and wham, better engine oil. but with the lean mix of colored orange sparkplugs, could prove to be more difficult with drivers wanting more kms/liter. i think id prefer the "more maintainance" than lose the drivers. unless i can source out a red colored sparkplug with the same fuel efficiency.

[dencio1976]

Could it be you are running the engines a touch on the lean side (possibly to maximize fuel economy)?

now that i think about it, this could be number 1 reason. then again it's a must on taxis. driver requirement sort of thing. drivers tend to always look for the best way to earn money. who wouldnt. problem is, if they think that the competition offers better fuel efficiency (as the 1st thing they look for in a cab, the rest follows like ride comfort reasons), some would leave. leaving some units without drivers.

in taxi business, like it or not, it's the drivers that mostly determine your success.

[ssalonga]

im rather interested on finding a solution rather than debate on it if it's ok.[/quote]

Excellent! Dencio, the first step in any good analysis is to standardize your data. Perhaps you could remember what mileage each vehicle had when the install was made. How many oil changes you made for each and the condition of the oil after each change. I assume you are changing oil every 5,000k? Did you do an initial compression test before the installation? How is the compression now? Remember, one way to measure valve erosion is the amount of compression leakage as the valve loses seal.

The low-grade oil may be the culprit. Several large taxi fleets I know are using a blend of Mobil 1 syn oil with an Oberon additive for extra duty vehicles. The oil is expensive (the supplier is a friend) and they change every 5K as required -- and they have a great looking fleet with no problems. They are all LPG and started that oil change regimen even before the installations.

If you consider a dedicated installation -- you save 50 kilos of hardware weight, the tank can be hidden away where the petrol tank was, and the 2E can be optimized for LPG and get even more economical consumption. After all gas supply is no longer an issue around metro manila.

Personally, I am keenly interested in the standardized data you could gather and I would gladly share what little I have since March. BTW my install is a NAiads kit, and I am perfectly happy with it, except now i want to close-loop the system! Has anyone installed such a system here yet???

cheers!

[ghosthunter]

it's true with the toyota engines regarding sludge problems. ive used low oil grades before and even now. im thinking i got away with it since i had drivers using premium gasoline before. the post regarding lubrication in premium gasoline may have been the key why i didnt get sludge problems with premium as compared with unleaded n lpg. ill be experimenting with the best suited oil. be trying toyota motor oils. i hear even some eg hatchback racers use this oil. any confirmation on this?

I use Shell's regular motor oil in my engine.

air filter change can be as fast as less than a month for our taxis. less air to pull in thru the intake meant more lpg to be pulled thru. therefore af is rich. but then engine would run cooler? wont it?

Yes, it can become rich and resulting with a slightly cooler cylinder temperatures. But if the LPG system was adjusted to compensate for the dirty filter, the engine will run lean on idle and then move to stoich or rich under load.

if it's color orange with the sparkplug that's the average color of what you'll find on taxi's because it seems to be the one with the best km/liter consumption. with a private car, this would be ok to lean. preferred with red colored sparkplugs to run cooler. this may definitely be one reason why engine temps run higher. but then again if u turn it to red, consumption aint as efficient as compared with the orange colored sparkplug.

http://www.gnttype.org/techarea/engine/plugs.html

what color of sparkplugs do you have normally on your lpg cars?

Brown. I thought it was indicating something bad since I assumed it should be light grey. I checked on the web on what "brown" meant. Light grey is good if you are using gasoline. Brown is the color if you are using LPG.

im seeing 2 potential problems now, low grade oil and lean mix(orange). with the 1st potential prob, that's easy. few additional pesos and wham, better engine oil. but with the lean mix of colored orange sparkplugs, could prove to be more difficult with drivers wanting more kms/liter. i think id prefer the "more maintainance" than lose the drivers. unless i can source out a red colored sparkplug with the same fuel efficiency.

You can try decreasing the time between the air filter change interval and using better oil.

[userfriendly]

last year, macro guys forgot to put water in the radiator one of the our first taxis installed with lpg kit. that made the the regulator cool. this moment came back to me when i thought about giving the engine cold air intake. then, with macro's latest design with the fuel injected type lpg kit (as i saw it being installed on a chevy van 6cyl and a ford expedition 8cyl), they were measuring water temp of the radiator. which got me to think that they might be on to this thought as well. im still feeling too lazy to continue with this project so i was thinking.. with the complex looking (more than the macro regulator anyways) regulator of naiadss, might it have ways of impeding water flow as well? for macro there none for sure with their 1st gen kit for carbs. or atleast i think it's their 1st gen kit.

.

Ask ko lang kung anong Chevy van. Ano pala contact no ng Macro? Chevy Venture ang oto ko and di kaya ng naiadss kabitan. Baka sakail sa macro pwede.

[dencio1976]

Excellent! Dencio, the first step in any good analysis is to standardize your data. Perhaps you could remember what mileage each vehicle had when the install was made. How many oil changes you made for each and the condition of the oil after each change. I assume you are changing oil every 5,000k? Did you do an initial compression test before the installation? How is the compression now? Remember, one way to measure valve erosion is the amount of compression leakage as the valve loses seal.

unfortunately i was not paying attention to the mileage. not all of our taxis have working mileage. 5k is the approximate change oil we do on our cabs. macro does the initial compression test and most resulted with balanced compression for the 4 pistons. a list of not passing the compression test we're either subjected to top overhaul or engine overhaul(machine shop spec'd)

The low-grade oil may be the culprit. Several large taxi fleets I know are using a blend of Mobil 1 syn oil with an Oberon additive for extra duty vehicles. The oil is expensive (the supplier is a friend) and they change every 5K as required -- and they have a great looking fleet with no problems. They are all LPG and started that oil change regimen even before the installations.

a blend of synthetic oil on taxi that approximately changes in 2-3weeks? wow that's a bigger price hike compared to the oil we use. we've used a petron brand Mo40 P85/liter since premium days. how much is estimated price on 1 liter on blended synthetic?

If you consider a dedicated installation -- you save 50 kilos of hardware weight, the tank can be hidden away where the petrol tank was, and the 2E can be optimized for LPG and get even more economical consumption. After all gas supply is no longer an issue around metro manila.

im not particular about this on our taxis.

Personally, I am keenly interested in the standardized data you could gather and I would gladly share what little I have since March. BTW my install is a NAiads kit, and I am perfectly happy with it, except now i want to close-loop the system! Has anyone installed such a system here yet???

cheers!

close loop as in returns? i dont think they've come up with that yet. not too sure thou

[dencio1976]

I use Shell's regular motor oil in my engine.

i use petron's Mo40. gt suggests toyota motor oil. even considering the blend of synthetic as far as its practicality. ill be trying it on my units. i only have 5units as of now, my dad owns the rest.

Yes, it can become rich and resulting with a slightly cooler cylinder temperatures. But if the LPG system was adjusted to compensate for the dirty filter, the engine will run lean on idle and then move to stoich or rich under load.
http://www.gnttype.org/techarea/engine/plugs.html

i guess the orange i was referring to was brown in your case. i named/colored it orange coz i thought it was in the middle of white and red. same color mostly. so the color is basically brown for me too for most with the ash fouled n some, oil fouled plugs. but they dont seem to have the red colored sparkplugs thou. i have 2 units with red colored sparkplugs.

Brown. I thought it was indicating something bad since I assumed it should be light grey. I checked on the web on what "brown" meant. Light grey is good if you are using gasoline. Brown is the color if you are using LPG.

amen. but then back when we were using premium we had the same color. brown. so i assumed i was getting the average for it atleast. 1st time i tried adjusting the lpg flow it was mostly colored white for the splugs. then drivers were complaining about high lpg fuel consumption and hard starts. so when i opened the screw a little just to compensate for the hard starts, drivers were then telling me that they suddenly saved on lpg fuel. when i checked to see the color of the sparkplugs, they were brown.

You can try decreasing the time between the air filter change interval and using better oil.

no prob with this one. i dont get black colored s plugs.

[dencio1976]

Ask ko lang kung anong Chevy van. Ano pala contact no ng Macro? Chevy Venture ang oto ko and di kaya ng naiadss kabitan. Baka sakail sa macro pwede.

Chevy Venture nga yun. i simply forgot the make of the chevy van kaya yun lang nilagay ko. basta engine nya is with 6cylinders. coz i was checking out the addons on the engine. they were using a laptop to monitor the water temp, rpm and some numbers i didnt checkout.

ill check with my dad regarding macro's number and contact. ive only been to macro mandaluyong twice. cant remember exactly were it is but it's near c5. i'll just get you the number when i get the chance tom morning.

[ghosthunter]

close loop as in returns? i dont think they've come up with that yet. not too sure thou

Closed loop system meaning the LPG fuel system is integrated with the car's EFI engine computer. This is compared to the current separated fuel and engine system we have on LPG converted vehicles.

[ssalonga]

Closed loop system meaning the LPG fuel system is integrated with the car's EFI engine computer. This is compared to the current separated fuel and engine system we have on LPG converted vehicles.

thanx ghosthunter, I meant that our mixture problems would probably be better controlled by an O2 sensor that could detects how much oxygen is still left in the exiting exhaust gases, and instantly adjust the mixture at the mixer or at the regulator. There are systems for MPI/EFI application but I am studying how to install to a non-EFI system engine (i.e. my carbed Pride). I was wondering if any of you had seen an actual application hereabouts?

Dencio, thanks for keeping this thread interesting! Your data is really interesting to me as I have very little feedback except when I hang out at NAIADS and MACRO every now and then!

[smdelfin]

Eto ba yung dilaw? Di ka na nag-try nun synth blend or yun pure synth? pwede na tong regular lang? Thanks!

I use Shell's regular motor oil in my engine.

[smdelfin]

Are you suggesting that the Macro LPG kit is better than the kit from naiadss, based on your experience and personal observation? For those of us who are planning conversion for the 1st time, are you suggesting that we take the Macro kit? Thanks!

im new here and would just like to share what i know or rather experienced with the LPG conversion kit. im a taxi operator with my dad and mostly use the Macro LPG conversion kit. (italy brand)

as compared to the naiadss lpg kit, i find that it's harder to maintain rather than using the macro lpg kit. however, both are fuel cost efficient.

[dencio1976]

thanx ghosthunter, I meant that our mixture problems would probably be better controlled by an O2 sensor that could detects how much oxygen is still left in the exiting exhaust gases, and instantly adjust the mixture at the mixer or at the regulator. There are systems for MPI/EFI application but I am studying how to install to a non-EFI system engine (i.e. my carbed Pride). I was wondering if any of you had seen an actual application hereabouts?

Dencio, thanks for keeping this thread interesting! Your data is really interesting to me as I have very little feedback except when I hang out at NAIADS and MACRO every now and then!

thanks ghosthunter. closed loop for the efi is available with Macro i think. im not too sure about it but what i know is that macro's efi lpg kit has it's own control unit and they were monitoring it via laptop. i dont think they have one for carbs yet. would prove to be very convenient for long term tuneups.

with regards to ignition timing, since the distributor for carbed engines come with vacuum advancers, there's not much to look here after advancing it at about 10deg. (im just assuming). the air control for carbed engines seem to be ok too with me. with the choke butterfly variating on engine speed, there'd be little to look at. hmm, on the other hand since the lpg is put directly on top of the carb(before the choke butterfly), the choke butterfly would be rendered useless. a closed choke butterfly would mean little to no lpg entry. reason for the choke butterfly was to supress air and not the fuel. so it would start easily to begin with. so i guess if you could inject the lpg right after the choke butterfly, that would be something. but it would be very interesting if it were controlled like the AFM or MAP found on a fuel injected engine. it'd be more accurate. better fuel efficiency in effect. cold air intake would also be good to consider.

[dencio1976]

Are you suggesting that the Macro LPG kit is better than the kit from naiadss, based on your experience and personal observation? For those of us who are planning conversion for the 1st time, are you suggesting that we take the Macro kit? Thanks!

we went with the Macro coz big companies like R&E(and their associates the green n yellow color designed cabs), their relatives MGE and EMP, biggest taxi company wallis corporation(with their associates as well, World, Romcat..which used to have naiadss as their 1st kit), all use Macro LPG conversion kits. arguably the better kit from their end. so that's why we went with macro lpg kit. but ive worked on some naiadss kit as well and i didnt really find a big difference when it came to fuel efficiency. only that the macro guys that installed our kits told us how they won R&E by crashing 1 of their taxis with their kit with a bus i think. no explosions. just that the tank was misplaced by the crash. no proof thou.

since i work mostly on macro kits, id have to recommend this over the naiadss kit. but i do like the naiadss' device directly on top of the carb as it does not need an external steel sheet to impede air from coming in to the carb. (forgot the name of that device on top of the carb). your choice still.

also that macro incorporates a crush washer with their pipe pittings to reinforce it from possible leaks. i dont know thou if naiadss has come up with it as well for their newer kits. driver complaints were regarding smells of the lpg from the trunk. that's why some taxi drivers ask for the brand of kits we use. they prefer macro. that's just the drivers thou. from my end, it's all about conditioning it.

ssalongga: btw, with regards to the blend of synthetic oil you were talking about, how much price difference am i looking at if i were to use a toyota motor oil at P110/L at toyocars in banawe? i seriously am considering this one. our units are all 2nd hand taxis. no bnew units.

[ssalonga]

ssalongga: btw, with regards to the blend of synthetic oil you were talking about, how much price difference am i looking at if i were to use a toyota motor oil at P110/L at toyocars in banawe? i seriously am considering this one. our units are all 2nd hand taxis. no bnew units.

Dencio, mahal pala yun! Just called up my friend -- its 1,000 per liter daw, altho they are out of stock at the moment waiting for the Oberon additive. Sorry, binibigyan lang nya ako every now and then. They mix them by the drum and the "butal" is collected, yun ang binibigay nya sa akin! He says the brand new cabs have been using it for 2 years na at marami naman day bumibili. Sold by Caliber Trading in San Juan, a guy named Danny Aquino. FYI nalang!

the real value of the "feedback" system is that the A/F ratio can be adjusted two or three times a second by the "ECU" which takes its readings from the O2 sensor, the ignition timing from the distributor and the vacuum reading from the manifold (below the throttle plate) and determines the correct mixture from a stoichometric map or graph in the flash memory of the ECU. I believe all the Italian's have them but I havent been able to get any direct info from Macro!

cheers!

[dencio1976]

Dencio, mahal pala yun! Just called up my friend -- its 1,000 per liter daw, altho they are out of stock at the moment waiting for the Oberon additive. Sorry, binibigyan lang nya ako every now and then. They mix them by the drum and the "butal" is collected, yun ang binibigay nya sa akin! He says the brand new cabs have been using it for 2 years na at marami naman day bumibili. Sold by Caliber Trading in San Juan, a guy named Danny Aquino. FYI nalang!

the real value of the "feedback" system is that the A/F ratio can be adjusted two or three times a second by the "ECU" which takes its readings from the O2 sensor, the ignition timing from the distributor and the vacuum reading from the manifold (below the throttle plate) and determines the correct mixture from a stoichometric map or graph in the flash memory of the ECU. I believe all the Italian's have them but I havent been able to get any direct info from Macro!

cheers!

wow! 1k/liter so that means 3.5x = 3.5k every 2weeks??? talo agad! that's no wonder why some have hiked boundaries. maybe i'll try the toyota motor oil first.

ive heard on a thread that placing O2 sensors on a manifold is achievable. but when you use macro's fi system lpg kits, i think they'll be tapping on to the injectors which carbed engines dont have. then again the distributor is vacuum actuated. hmm, it'll take some mods to really get a carbed engine with a closed system.

with O2 sensors that can be placed on the exhaust manifold, wideband O2 tuner as well.. inputs to a placed ecu.. what about for fuel management? system has to come from the lpg kit. what do think? maybe we can come up with something.

[ghosthunter]

Eto ba yung dilaw? Di ka na nag-try nun synth blend or yun pure synth? pwede na tong regular lang? Thanks!

Yup, thats the one in the yellow containers. I never saw the need to get a synthetic oil or blend. I just stuck with my regular tune up & and change oil schedule. For my personal use, I do not find a need to upgrade my motor oil.